My son was backing out of a parking spot at a strip mall. He released some pressure on the brake and indicated that the car lurched backwards and even though he reapplied full pressure to the brakes, he hit the car at the curb resulting in damage to our Tucson, but luckily not the to the other car. The Rear Cross-Traffic Collision-Avoidance Assist system did not engage, but my son indicated that the rear distance warning system did beep. I am concerned due to the sudden acceleration/lurching incident my son experienced and this is not acceptable in any car. I ask the NHTSA to see if other Hyundai Tucson or Kia Sportage owners, especially with the Hybrid engine are experiencing this.